sub groups may not hold your money, but what is the CTG / WTS arrangement. Let's say 1 CTG guy loses a lot of money (more money than CTG has as their 'security deposit' with WTS. Now WTS is losing money on CTG. Is the arrangement that WTS still must pay CTG's traders who are up?
It could be, it might not be. I'd ask in an email from the WTS people (don't trust the answer from the CTG people). Then you can feel more comfortable, regardless of where the money is held.